Pediatrics

Recurrent Pneumonia

OVERVIEW: What every practitioner needs to know

Are you sure your patient has recurrent pneumonia? What are the typical findings for this disease?

Recurrent pneumonia is defined as 3 or more episodes of pneumonia in a lifetime or 2 or more episodes within a six-month period.

The most common symptoms are cough, wheeze, dyspnea, and chest discomfort.

What other disease/condition shares some of these symptoms?

Pneumonia is often diagnosed clinically without the utilization of a chest radiograph (CXR). If symptoms resolve as expected, a follow-up CXR may not be obtained even if there was an initial CXR at the time of diagnosis. For the child with recurrent chest symptoms, lack of serial CXR’s can make distinguishing “recurrent” from “persistent” pneumonia challenging.

If the radiographic abnormality is persistent, particularly in a specific area of the lung, a congenital anomaly or airway obstruction is more likely than if the abnormalities come and go and are found in different regions of the lung. Therefore, the evaluation of “persistent” may be different than for truly “recurrent” pneumonia.

Common cause of recurrent pneumonia #1: Asthma. The mechanism is viral infection that produces both fever and an asthma exacerbation. Increased airway edema, bronchoconstriction, and excessive mucus production with mucus plugging produce the abnormalities on CXR. The fever, abnormal auscultation, and abnormal CXR lead the clinician to diagnose pneumonia. The patient with “recurrent pneumonias” due to repeated asthma exacerbations may have cough, wheeze, or dyspnea with triggers other than upper respiratory infection (URI), such as exercise, allergen, or irritant exposure. They may not always have fever when they have “pneumonia.” Their personal history may reveal atopy such as eczema or allergic rhinitis, and the family history is usually atopic. Pulmonary function testing may be normal or may show reversible airflow obstruction or bronchial reactivity. Methacholine or exercise challenge testing, not often required for diagnosis, are likely to be positive for asthma. Aggressive asthma therapy with better asthma control usually prevents further episodes of “pneumonia.”

Common cause of recurrent pneumonia #2: Immunodeficiency. When the infections are limited to the upper and lower airways, the deficiency is usually a B-cell or partial B-cell deficiency. If the recurrent pneumonias are associated with significant infections outside the respiratory tract, the deficiency is usually T-cell (or T- and B-cell deficiency) or possibly neutrophil dysfunction. A clue that immunodeficiency may be the underlying cause is when the isolated organisms are “opportunistic” and may not occur in the immunocompetent host. Intravenous immunoglobulin infusion may help minimize the pneumonias if hypogammaglobulinemia is present.

Common cause of recurrent pneumonia #3: Aspiration. Aspiration while swallowing or after gastro-esophageal reflux often causes recurrent pneumonia, even in children who appear to be neurologically intact. A careful history may indicate that aspiration is the underlying cause. Modified barium swallow, upper GI radiographs, impedance/pH probe, or milk scintiscan may help confirm aspiration. If medical management is not successful, airway evaluation should be performed to exclude laryngeal cleft or occult H-type tracheo-esophageal fistula. Lipid-laden macrophages obtained during bronchoscopy and lavage are a controversial marker of aspiration.

Less common cause of recurrent pneumonia #1: Impaired mucociliary clearance and ineffective cough. Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) are the most frequent causes of abnormal mucociliary clearance in children. All states currently screen for CF in the newborn period; sweat testing or DNA analysis should be considered even if the newborn screen was negative, particularly if steatorrhea or growth failure are also present. Patients with PCD almost all have profuse rhinorrhea and wet cough starting in the newborn period; approximately 50% will have situs inversus. Bronchiectasis that may have developed as the result of repeated infections is another cause of abnormal mucociliary clearance that can lead to recurrent pneumonia. If the patient’s cough is ineffective due to tracheomalacia, chest wall restriction (e.g., scoliosis), or weakness (e.g., Duchenne muscular dystrophy or spinal muscular atrophy), then retained secretions will promote recurrent pneumonia.

What laboratory studies should you request to help confirm the diagnosis? How should you interpret the results?

The initial laboratory evaluation should be tailored to the specific underlying diagnosis that is most likely the explanation for the recurrent pneumonia. Screening for immunodeficiency is usually indicated (immunoglobulins G, A, M, E and WBC with differential); more extensive studies are appropriate if T-cell deficiency or neutrophil dysfunction is suspected (T- and B-cell numbers and function, response to immunizations, neutrophil function tests). A sweat chloride test or DNA analysis should be considered, even if the newborn screen for CF was negative.

If asthma is suspected and the child is capable of performing pulmonary function testing, pre- and post-bronchodilator flow volume loops may reveal reversible airflow obstruction or bronchial reactivity consistent with asthma. The fraction of exhaled nitric oxide (FeNO) may be elevated, suggesting eosinophilic airway inflammation. Challenge testing (methacholine or exercise) may be positive but seldom needed for diagnosis.

Bronchoscopy with bronchoalveolar lavage can help exclude airway malformation or damage as the underlying explanation and assess cell types, hemosiderin-laden macrophages (a marker of alveolar hemorrhage), and lipid-laden macrophages (a possible marker for aspiration). Mucosal biopsy for electron microscopic evaluation of the ciliary ultrastructure may be indicated to diagnose PCD; the biopsy can be from the nasopharynx or the airways.

Would imaging studies be helpful? If so, which ones?

Obtaining serial CXR’s will help determine that pneumonias have occurred and have been recurrent rather than persistent. They will also help determine if the abnormalities are usually in the same area or if they have occurred in different lung segments. It may be challenging to have the opportunity to view all the radiographs at the same time and have them all reviewed by a pediatric radiologist, but this is highly recommended.

Chest computerized tomography (CT scan) usually helps further define the location of and extent of any airway or parenchymal abnormality.

A modified barium swallow with speech therapy present and an upper GI series are often helpful in assessing aspiration.

If you are able to confirm that the patient has recurrent pneumonia, what treatment should be initiated?

Immediate treatment depends on the severity of the acute illness. Supplemental O2 should be provided if hypoxia is present. Antibiotics are usually given either orally or intravenously, and should be selected based on culture results or organisms suspected based on the underlying illness. If poor secretion control or ineffective cough is suspected, airway clearance such as chest physical therapy and cough assist devices should be utilized. If segmental airway obstruction is suspected, bronchoscopy may be diagnostic and therapeutic. If asthma is suspected, aggressive inhaled bronchodilators (short-acting beta agonists and anticholinergics) along with systemic corticosteroids will be beneficial.

Long-term therapy should be directed at the underlying cause. Children with CF should be cared for in specialized accredited CF centers. Monthly IVIG infusions should help prevent pneumonia for children with hypogammaglobulinemia. There are a multitude of airway clearance techniques available to facilitate mucus clearance for children with impaired mucociliary clearance that can be utilized several times daily in the home setting. Children with recurrent pneumonia due to asthma may benefit from daily controller therapy with inhaled corticosteroids or leukotriene modifiers. Elimination of environmental exposures will help reduce the frequency of recurrent pneumonia.

Surgical intervention for children with persistent pneumonia due to congenital foregut malformations is usually curative. If esophageal reflux disease is causing the recurrent pneumonia and fails medical management, fundoplication may be beneficial.

What are the adverse effects associated with each treatment option?

N/A

What are the possible outcomes of recurrent pneumonia?

The prognosis depends on the underlying cause. Successful asthma therapy usually prevents further episodes of pneumonia. The average age of death for patients with CF is now 38.5 years and consistently increasing as new therapies become available. If aspiration can be eliminated or minimized, the recurrent pneumonia usually resolves. Successful assistance with airway clearance for patients with weakness or mucociliary clearance defects will also reduce the frequency of pneumonia.

What causes this disease and how frequent is it?

There are no prevalence figures for recurrent pneumonia. Children with chronic lung problems are frequently ill more often during the winter viral season during seasonal epidemics of respiratory syncytial virus (RSV) and influenza.

All recommended childhood immunizations should be provided, including annual influenza immunization. Avoiding crowded environments and good handwashing can limit the spread of viral illness. Poor air environments and tobacco poisoning should be avoided.

CF is an autosomal recessive disease that affects about one of every 3200 live Caucasian births. Abnormal DNA mutations can be identified in almost all cases of CF. PCD is an autosomal recessive disease that affects an estimated one in 20,000 to 60,000 individuals. DNA abnormalities as causes of PCD can be found in only about 30% of the cases. A variety of immunodeficiency syndromes have a genetic basis.

How do these pathogens/genes/exposures cause the disease?

N/A

Other clinical manifestations that might help with diagnosis and management

If the radiographic abnormalities are persistent rather than recurrent, it is more likely that a structural problem exists. Congenital foregut malformations include: congenital cystic adenomatoid malformation (CCAM), congenital pulmonary airway malformation (CPAM), bronchogenic cysts, congenital lobar overdistention, sequestration, and esophageal duplication. Surgical resection is curative. Retained foreign body, endobronchial tumor, or extrinsic airway compression can also lead to persistent pneumonia and are identified at the time of bronchoscopy.

What complications might you expect from the disease or treatment of the disease?

Complications depend on specific treatments offered for specific diseases, and are generally minimal.

Are additional laboratory studies available; even some that are not widely available?

N/A

How can recurrent pneumonia be prevented?

All childhood immunizations should be provided, including annual influenza immunizations.

Tobacco poisoning should be avoided.

Genetic counseling may be appropriate for families with CF, PCD, and immunodeficiency states.

Many children with chronic lung problems also have nutritional challenges. Supporting adequate nutrition facilitates cough strength and efficiency. Children with CF with good nutrition have a survival advantage over those who do not.

Ongoing controversies regarding etiology, diagnosis, treatment

Aerosolized antibiotics and mucolytics have documented benefit in CF, but there is limited data supporting their use in other disease states. Although a wide variety of airway clearance techniques are available, there are no comparative studies to favor one over the other.